In conventional output drivers, a core voltage data signal is typically converted to a relatively higher voltage signal. In addition to the data signal, various other control signals output from the core to provide for activation of the driver or to bring the driver to a power down mode or high-impedance tri-state mode. These control signals are often converted from the lower core voltage to the higher voltage using a level shifter. For the conversion in the level shifter to take place correctly, it is assumed that the core voltage is present before, or at least not later than, the higher voltage.
However, if the core voltage is produced from the higher voltage using a voltage regulator, then the core voltage would not be present before the higher voltage during the engaging/switching-on of the supply voltage. In such a case, while the driver is connected to the supply voltage, the control signals would be at an undefined level, because the level shifter has not yet received an input signal and the core has not yet received the supply voltage. When engaging/switching-on the supply voltage in such a case, the output driver may not be safely brought to the power down or tri-state condition. This, in turn, may produce undesirable high cross currents in the output driver.